Epoxy resins and silicone resins (also referred to as polysiloxane resins) are used as encapsulants for semiconductor devices such as light emitting diodes (LED) or as a matrix having a phosphor distributed therein in white LED. Hybrid resins that include a silicone resin in combination with an epoxy resin also have been developed (Patent Documents 1, 2, and 3). Furthermore, depending on the application, mixing an additive such as silica into the above resins has been also contemplated.
Typical and well known curing agents for epoxy resins include polyamine-based curing agents, carboxylic acid anhydride-based curing agents, and phenol resin-based curing agent. These curing agents are a compound that has a functional group that reacts with an epoxy group. Other curing agents include the types of agents that catalyze the self-polymerization reaction (cationic polymerization reaction involving ring-opening) of an epoxy group. Such types of curing agents include combinations of silanol and a metal complex (a complex that contains Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, or Zr) (Patent Documents 4 and 5).
As curing catalysts for condensation-cured silicone resins, gallium compounds are known (Patent Document 6).